The other 20 percent have symptoms such as fever, headache, body aches, nausea, vomiting and sometimes swollen lymph glands. Some develop a rash on the chest, stomach and back. Symptoms may last anywhere from a few days to several weeks.
Severe forms of West Nile, which affect the nervous system, can be life-threatening. The NIH says that the following symptoms need prompt medical attention: muscle weakness, stiff neck, weakness in one arm or leg, confusion or a change in ability to think clearly and loss of consciousness or coma.
4. How can I prevent catching West Nile?
The CDC recommends using an insect repellent that contains one of the following ingredients: DEET, picardin, oil of lemon eucalyptus (or a synthetic version of this oil, called PMD), or IR3535. These ingredients are suggested by the Environmental Protection Agency because they provide reasonably long-lasting protection against mosquito bites.
The CDC also suggests wearing long sleeves and pants, or staying indoors, at dusk and dawn, when mosquitoes are most active.